APA (7th ed.) Citation

Gaarder Jostein. (2015). Sophies World. Weindenfuld.

Chicago Style (17th ed.) Citation

Gaarder Jostein. Sophies World. New York: Weindenfuld, 2015.

MLA (9th ed.) Citation

Gaarder Jostein. Sophies World. Weindenfuld, 2015.